1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 */ 36 37 #include <sys/cdefs.h> 38 #include "opt_ddb.h" 39 40 #include <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/linker.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mutex.h> 46 #include <sys/systm.h> 47 48 /* 49 * Autoconfiguration subroutines. 50 */ 51 52 /* 53 * "Interrupt driven config" functions. 54 */ 55 static STAILQ_HEAD(, intr_config_hook) intr_config_hook_list = 56 STAILQ_HEAD_INITIALIZER(intr_config_hook_list); 57 static struct intr_config_hook *next_to_notify; 58 static struct mtx intr_config_hook_lock; 59 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF); 60 61 /* ARGSUSED */ 62 static void run_interrupt_driven_config_hooks(void); 63 64 /* 65 * Private data and a shim function for implementing config_interhook_oneshot(). 66 */ 67 struct oneshot_config_hook { 68 struct intr_config_hook 69 och_hook; /* Must be first */ 70 ich_func_t och_func; 71 void *och_arg; 72 }; 73 74 static void 75 config_intrhook_oneshot_func(void *arg) 76 { 77 struct oneshot_config_hook *ohook; 78 79 ohook = arg; 80 ohook->och_func(ohook->och_arg); 81 config_intrhook_disestablish(&ohook->och_hook); 82 free(ohook, M_DEVBUF); 83 } 84 85 /* 86 * If we wait too long for an interrupt-driven config hook to return, print 87 * a diagnostic. 88 */ 89 #define WARNING_INTERVAL_SECS 60 90 static void 91 run_interrupt_driven_config_hooks_warning(int warned) 92 { 93 struct intr_config_hook *hook_entry; 94 char namebuf[64]; 95 long offset; 96 97 if (warned < 6) { 98 printf("run_interrupt_driven_hooks: still waiting after %d " 99 "seconds for", warned * WARNING_INTERVAL_SECS); 100 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 101 if (linker_search_symbol_name( 102 (caddr_t)hook_entry->ich_func, namebuf, 103 sizeof(namebuf), &offset) == 0) 104 printf(" %s", namebuf); 105 else 106 printf(" %p", hook_entry->ich_func); 107 } 108 printf("\n"); 109 } 110 KASSERT(warned < 6, 111 ("run_interrupt_driven_config_hooks: waited too long")); 112 } 113 114 static void 115 run_interrupt_driven_config_hooks(void) 116 { 117 static int running; 118 struct intr_config_hook *hook_entry; 119 120 TSENTER(); 121 mtx_lock(&intr_config_hook_lock); 122 123 /* 124 * If hook processing is already active, any newly 125 * registered hooks will eventually be notified. 126 * Let the currently running session issue these 127 * notifications. 128 */ 129 if (running != 0) { 130 mtx_unlock(&intr_config_hook_lock); 131 return; 132 } 133 running = 1; 134 135 while (next_to_notify != NULL) { 136 hook_entry = next_to_notify; 137 next_to_notify = STAILQ_NEXT(hook_entry, ich_links); 138 hook_entry->ich_state = ICHS_RUNNING; 139 mtx_unlock(&intr_config_hook_lock); 140 (*hook_entry->ich_func)(hook_entry->ich_arg); 141 mtx_lock(&intr_config_hook_lock); 142 } 143 144 running = 0; 145 mtx_unlock(&intr_config_hook_lock); 146 TSEXIT(); 147 } 148 149 static void 150 boot_run_interrupt_driven_config_hooks(void *dummy) 151 { 152 int warned; 153 154 run_interrupt_driven_config_hooks(); 155 156 /* Block boot processing until all hooks are disestablished. */ 157 TSWAIT("config hooks"); 158 mtx_lock(&intr_config_hook_lock); 159 warned = 0; 160 while (!STAILQ_EMPTY(&intr_config_hook_list)) { 161 if (msleep(&intr_config_hook_list, &intr_config_hook_lock, 162 0, "conifhk", WARNING_INTERVAL_SECS * hz) == 163 EWOULDBLOCK) { 164 mtx_unlock(&intr_config_hook_lock); 165 warned++; 166 run_interrupt_driven_config_hooks_warning(warned); 167 mtx_lock(&intr_config_hook_lock); 168 } 169 } 170 mtx_unlock(&intr_config_hook_lock); 171 TSUNWAIT("config hooks"); 172 } 173 174 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST, 175 boot_run_interrupt_driven_config_hooks, NULL); 176 177 /* 178 * Register a hook that will be called after "cold" 179 * autoconfiguration is complete and interrupts can 180 * be used to complete initialization. 181 */ 182 int 183 config_intrhook_establish(struct intr_config_hook *hook) 184 { 185 struct intr_config_hook *hook_entry; 186 187 TSHOLD("config hooks"); 188 mtx_lock(&intr_config_hook_lock); 189 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 190 if (hook_entry == hook) 191 break; 192 if (hook_entry != NULL) { 193 mtx_unlock(&intr_config_hook_lock); 194 printf("config_intrhook_establish: establishing an " 195 "already established hook.\n"); 196 return (1); 197 } 198 STAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links); 199 if (next_to_notify == NULL) 200 next_to_notify = hook; 201 hook->ich_state = ICHS_QUEUED; 202 mtx_unlock(&intr_config_hook_lock); 203 if (cold == 0) 204 /* 205 * XXX Call from a task since not all drivers expect 206 * to be re-entered at the time a hook is established. 207 */ 208 /* XXX Sufficient for modules loaded after initial config??? */ 209 run_interrupt_driven_config_hooks(); 210 return (0); 211 } 212 213 /* 214 * Register a hook function that is automatically unregistered after it runs. 215 */ 216 void 217 config_intrhook_oneshot(ich_func_t func, void *arg) 218 { 219 struct oneshot_config_hook *ohook; 220 221 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK); 222 ohook->och_func = func; 223 ohook->och_arg = arg; 224 ohook->och_hook.ich_func = config_intrhook_oneshot_func; 225 ohook->och_hook.ich_arg = ohook; 226 config_intrhook_establish(&ohook->och_hook); 227 } 228 229 static void 230 config_intrhook_disestablish_locked(struct intr_config_hook *hook) 231 { 232 struct intr_config_hook *hook_entry; 233 234 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 235 if (hook_entry == hook) 236 break; 237 if (hook_entry == NULL) 238 panic("config_intrhook_disestablish: disestablishing an " 239 "unestablished hook"); 240 241 if (next_to_notify == hook) 242 next_to_notify = STAILQ_NEXT(hook, ich_links); 243 STAILQ_REMOVE(&intr_config_hook_list, hook, intr_config_hook, ich_links); 244 TSRELEASE("config hooks"); 245 246 /* Wakeup anyone watching the list */ 247 hook->ich_state = ICHS_DONE; 248 wakeup(&intr_config_hook_list); 249 } 250 251 void 252 config_intrhook_disestablish(struct intr_config_hook *hook) 253 { 254 mtx_lock(&intr_config_hook_lock); 255 config_intrhook_disestablish_locked(hook); 256 mtx_unlock(&intr_config_hook_lock); 257 } 258 259 int 260 config_intrhook_drain(struct intr_config_hook *hook) 261 { 262 mtx_lock(&intr_config_hook_lock); 263 264 /* 265 * The config hook has completed, so just return. 266 */ 267 if (hook->ich_state == ICHS_DONE) { 268 mtx_unlock(&intr_config_hook_lock); 269 return (ICHS_DONE); 270 } 271 272 /* 273 * The config hook hasn't started running, just call disestablish. 274 */ 275 if (hook->ich_state == ICHS_QUEUED) { 276 config_intrhook_disestablish_locked(hook); 277 mtx_unlock(&intr_config_hook_lock); 278 return (ICHS_QUEUED); 279 } 280 281 /* 282 * The config hook is running, so wait for it to complete and return. 283 */ 284 while (hook->ich_state != ICHS_DONE) { 285 if (msleep(&intr_config_hook_list, &intr_config_hook_lock, 286 0, "confhd", hz) == EWOULDBLOCK) { 287 // XXX do I whine? 288 } 289 } 290 mtx_unlock(&intr_config_hook_lock); 291 return (ICHS_RUNNING); 292 } 293 294 #ifdef DDB 295 #include <ddb/ddb.h> 296 297 DB_SHOW_COMMAND_FLAGS(conifhk, db_show_conifhk, DB_CMD_MEMSAFE) 298 { 299 struct intr_config_hook *hook_entry; 300 char namebuf[64]; 301 long offset; 302 303 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 304 if (linker_ddb_search_symbol_name( 305 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf), 306 &offset) == 0) { 307 db_printf("hook: %p at %s+%#lx arg: %p\n", 308 hook_entry->ich_func, namebuf, offset, 309 hook_entry->ich_arg); 310 } else { 311 db_printf("hook: %p at ??+?? arg %p\n", 312 hook_entry->ich_func, hook_entry->ich_arg); 313 } 314 } 315 } 316 #endif /* DDB */ 317